Thread cutter for tube-working machines



April 26, 1927.

w. T. DAVIS THREAD CUTTER FOR TUBE WORKING MACHINES Filed Avril 20. 1925 '5 heet s-Sheet 1 INVENTOR A ril 26, 1927.

w. -r. DAVIS THREAD CUTTER FOR TUBE WORKING MACHINES Filed Anril 20. 1923 3 e' s sheet 2 illll" l 6 1927' w. T. DAVIS THREAD CUTTER FOR TUBE WORKING MAGHINEIS Filed Avril 1923 3 Sheets-Sheetii INVENTOR Patented Apr. 26 1927.

UNITED STATES PATENT OFFICE.

WALTER T. DAVIS, OF WHEELING, WEST VIRGINIA, ASSIGNOR T0 WHEELING STAMP- ING COMPANY, OF WHEELING, WEST VIRGINIA, A. GORPORATIONOF WEST VIR GINIA.

THREAD CUTTER FOR TUBE-WORKING MACHINES.

Application filed April 20, 1923. Serial No. 633,443.

The present invention relates broadly to the manufacture of colla sible tubes, and more particularly to threa -cutters for tubeworking machines.

It has heretofore been-proposed to form the threads in the necks of collapsible tubes by a rolling and pressing operation, without or substantially without the removal of any of the material of the tube. This thread-formingoperation has usually been carried out by supporting the tube to be threaded on a rotating mandrel and causing the roll or rolls to engage the rotating neck of the tube, said roll or rolls having threads of the desired pitch in the cylindrical surface or surfaces thereof and being pressed against said rotating neck with sufficient pressure to cause the roll-or rolls to be frictionally rotated thereby. This operation fre uentlv resulted in the formation of impeliect threads or in the distortion of the neck, or in both, the distortion of the neck being due to the pressure of the roll or rolls thereagainst.

The present invention aims to overcome these disadvantages of the rolling and pressing method b the provision of means for forming the t reads by a cutting operation, such cutting operation involving an actual removal of material from the tube neck as distinguished from the rolling and pressing operation which involves a displacement of the material of the tube neck.

In the accompanying drawings:

Figure 1 is a side elevation, partly broken away, of a machine embodying my invention,

Figure 2 is a plan view of the threading means and adjacent parts of the machine,

Fi re 3 is a vertical sectional view on the hue III-III of Figure 2,

Fi re 4 is a vertical longitudinal 'sectiona view of a portion of the cutter-carryingvlever,

igure 5 is a view, partly in side elevation and partly in vertical section, the section being taken on the line VV of Figure 3, and

Figures 6 and 7 are a side elevation and edge view, respectively, of the cutter member.

While my invention is broadly applicable to various types of machines for manufac- -being journaled in the turing'collapsible tubes, I have herein shown tary mandrel-carrying turret 2 which is de-- signed to have a step-by-step rotation, and which carries four tube-ho ding rotatable mandrels 3. The actuating gears for the turret and mandrels are indicated by the reference numeral 4, these gears being driven through a belt 5 from a power-shaft 6,-the latter having fast and loose pulleys7 thereon.

The machine may be provided with a feed hopper 8 of any well-known selective character and adapted to feed the caps into a suit able delivery chute 9- having an overflow spout 10. The chute 9. delivers the 'caps'to a cap-applying device 11. Thefeed hopper is mounted for rotation and is provided for that purpose with a bevel gear 12 meshing with a bevel gear 13 on a shaft 14, the latter bracket 15 which supports the hopper. The shaft 14. is driven from a shaft 16 through a belt 17 which engages pulleys 18 and 19 on the shafts 14 and 16, respectively, the shaft 16 bein driven from the power-shaft 6 through a be t 20 engaging pulleys 2 1 and 22 on the said shafts 6 and 16, respectively.

In the operation of the machine, the mandrcl-carrying turret is given a step-by-step I rotation to-carry each mandrel successively into each of four operative positions 90 degrees apart. At one operative position into which each mandrel is brought, a collapsible tube to be operated upon is placed thereon by an operative; at the second position, the neck of each .tube is threaded and the end thereof trimmed to open up the discharge passage therein; at the third position, each tube is cut to length by a cutter 23, and a cap applied to the threaded neck thereof, and at the fourth position, each tube is removed from its mandrel by the operative.

The thread-cutting means of the present face of the arm of the lever shoulder 41 integrally end of a pin 42 slidably 'tical bearing 43 presently brought out.

invention is illustrated in detail in Figures 2 to 7, inclusive, and comprises a cutter 24 secured by a screw-bolt 25 on the end of a lever 26. The cutter-carrying lever 26 is fixed intermediate its ends upon a shaft 27 journaled at its ends in bearings formed in brackets 28 and 29, which are bolted to the frame of the machine. Extending through the end of the lever 26 opposite to that on which the cutter 24 is secured, is an opening, the axisof which lies in a vertical plane, and adjustably secured in the opening by means of a set-screw 30 is a follower-pin 31 having its lower end double-beveled to a knife-edge to engage the threads of a leadscrew 32. This lead-screw is carried by a shaft 33 journaled in the frame A and driven from the shaft 16 through a pinion 34 on the shaft 33 meshing with a gear'35 on the shaft 16.

A coil-spring 36 surrounds the shaft 27 intermediate the lever 26 and the bracket 29, and has one end fastened to the lever and the other end fastened to the bracket, the tension of said spring being exerted to rotate said lever in a direction to move the edge of the follower-pin 31 out of engagement with the lead-screw 32 and to lower the cutter 24 out of operative osition.

A flat spring 37 is astened to the under 26 which carries the cutter 24, this spring being secured to the lever by a bolt 38 which passes through the lever and is screwed into a threa ed opening in the sprin adjacent the end thereof which is nearest the fulcrum of the lever. A screw 39 engages in a threaded bore in the lever 26 and abuts at its end against spring 37 intermediate the ends of the latter, whereby by adjusting the screw, the free end, portion of the spring 37 may be sprung more or'less away from the under face of the lever-arm for a purpose to be A lock-nut 40 on the screw 39 engages the upper face of the leverarm and locks the screw in adjusted position.

The spring 37 has a downwardly directed formed on the free end thereof, which is engaged by the upper mounted in a verformed in a housing B which surrounds the shaft 16. The lower end of the in 42 is engaged by a cam member 44 carried by said shaft 16. v

he shaft 16 also has mounted thereon a collar 45 having a cam groove 46 formed in the periphery thereof. This cam groove is engaged by the lower end of a pin 47, which is fixed to a carriage C slidably mounted upon the upper face of the housing B, said pin extending through a longitudinal slot 48 in said housing. The sliding carriage (3 has adjustably mdhnted thereon with the lead-screw 32,

sliding in its bearings in a holder 49 for a neck-trimmer 50, the latter being moved into and out of operative position once during each revolution of the shaft 16, as will be obvious.

It will be apparent that during each revolution of the shaft 16, the cam 44 raises the pin 42, the latter, through its engagement with the spring 37, effecting a rocking of the lever 26 in a counter-clockwise direction, (Figure 3) and in opposition to the spring 36, thereby lowering the pin 31 to effect engagement of its beveled lower end with the lead-screw 32 and raising the cutter 24 into operative position with respect to the position occupied by the neck of a tube to be threaded. Byadjusting the screw 39 to spring the free end portion of the spring 37 a greater or less distance away from the arm of the lever 26, theoperative position of the cutter 24 may be very accurately adjusted.

The inoperative position of the lever 26 and the parts carried thereby is illustrated in Figure 1, and the operative position of these parts is illustrated in Figures 2, 3 and 5. It will be notedthat in the inoperative position of the parts, the lever 26 is held by the spring 36 in engagement with the bracket 28. As soon as the cam '44 engages and raises the in 42 to effect movement of the cutter 24 into operative position with respect to the neck of a'tube D (Figures 2 and 5), the beveled edge of the pin 31 is brought into engagement with the rotating leadscrew 32'. At this moment the cutter 24 is in engagement with the end of the neck surface of the tube D, and thereafter the lever 26, through the engagement of the pin 31 is gradually moved toward the bracket 29, thereby putting the spring 36 under compression, the shaft 27 the brackets 28 and 29. The cam 44 is so shaped as to maintain the pin 42 in the raised position until the neckof the tube has been threaded from end-to-end, as indicated in Figure 5, and then to permit said pin to fall. As soon as this occurs, the spring 36 rocks the lever 26 in a clockwise direction (Figure 3), thereby eifectin disengagement of the pin 31 from the lead -screw 32, and, immediately that this occurs, the said spring 36 moves the'lever 26 into engagement with the bracket 28, which is the normal inoperative position of the lever and the parts carried thereby. It

is obvious-that by removing the cam 44 and substituting a differently shaped cam, the

threading mechanism may be readily adapted to thread tubes having longer or shorter necks, or having necks of a greater or less diameter. Moreover, the adjustable spring 37 affords means for accurately adjusting the operative position of the cutter.

Referring to Figures 6 and 7, it will be seen that the cutting point 51 of the cutter member 24 lies in an arcuate edge 52 formed by the intersection of bevel faces 53 and 54 on the periphery of the cutter member. The point 51 also'lies in the substantially radial face 55 formed by cutting away the cutter member as shown. When the cut-- ting point 51 becomes dull, the cutter member may be sharpened by grinding the face 55, thereby movin the cutting point 51 further back in the edge 52. It will be seen that the cutter is of such form that it may be repeatedly ground until the point 51 has been moved around substantially to the point 56 constituting the opposite end of the edge 52. Such form of cutter is, therefore, extremely economical because it admits of substantially the entire cutter member being used up before it has to be discarded. It will also be apparent that the mounting of the cutter '24 by means of the screw-bolt 25 admits of the cutter member being adjusted as the same is sharpened, from time to time, to properly position the cutting point 51 with respect to the tube necks.

An important advantage arising from the invention is that, due to theprovision of means for forming the threads in the necks of the tubes by a cutting operation, the necks are relieved of the ressure tending to deform the same which is exerted by the roll or rolls in the forming and pressing operation, in which the friction between the tube neck and the roll or rolls must be suificient to cause the roll or rolls to be rotated by the rotating neck and to cause the threads on the roll or rolls to displace material of the neck in order to form the threads therein.

Another advantage arising from the invention is that it enables the formation of more erfect threads in the necks of the tubes t an heretofore.

A further advantage arising from the invention is that it provides a s ecial form of cutter member which may sharpened until the cutter member is substantiallfy completely used up thereby providing or economy of operation.

While I have shown and described a preferred embodiment of my invention, it will be understood that the drawings do not define the-limits of the invention, as changes may be made in the construction, arrangement and operation therein disclosed without departing from the s irit of my invention or scope of my broa er claims.

I claim:

1. In a collapsible tube-working machine,

lube-supporting and rotating means, a lever fulcrumed intermediate its ends and mounted for bodily movement in the direction of its pivotal axis, acutter mounted .upon an arm of said lever and adapted to be moved thereby into and out of operative position with respect to the neck of a tube on said e repeatedlysupporting means, a lead-screw, follower means carried by the other arm of said lever and adapted to engage the threads of said lead-screw to cause a bodily movement of said lever in the direction of its pivotal axis, said lever normally maintaining said cutter in inoperative position and said follower means outof engagement with said lead-screw, and means for rocking said lever into a position in which said cutter is in operative position and in which said follower means is in engagement with said leadscrew and for maintaining said lever in said position during a threading operation, substantially as described. 7

2 In a collapsible tube-working machine, tube-supporting and rotating means, a lever fixed intermediate its ends upon a shaft slidable and rotatable in spaced bearin s, a cutter mounted upon one arm of said ever and adapted to be moved thereby into and out of operative position with respect to the neck of a tube on said supporting means, a lead-screw, follower means carried by the other arm ofsaid, lever and adapted to enga e the threads of said lead-screw to cause a Iiodily movement of said lever in the direction of its pivotal axis, a coil spring surrounding said shaft between said lever and one of said bearings and tending to rock said shaft in a direction to maintain said cutter .in inoperative position and said follower means out of engagement with said leadscrew and to move said lever towards the other of said bearings, and means for rocking said lever into a position in which said cutter is in operative position and in which said followermeans is in engagement with said lead-screw and for maintaining said lever in said position during a threading operation, substantially as described.

3. In a collapsible tube-working machine, tube-supporting and rotating means, a lever fulcrumed intermediate its ends and mounted for bodily movement in the direction of its pivotal axis, a cutter mounted upon an arm of said lever and adapted to be moved thereby into and out of operative position with respect to the neck of a tube on said supporting means, a lead-screw, follower means carried by the other arm of said lever and adapted to engage the threads of said lead-screw to cause a .bodily movement of said lever in the direction of its pivotal axis, said lever normally maintaining said cutter in inoperative position and said follower means out of engagement with said lead-screw, a flat spring fastened to the cutter supporting arm of said lever, adjustable means for springing said spring away from said arm, and cam means engageable with said spring for rocking said lever into a position in which said cutter is in operative position and in which said follower means is in engagement with said lead-screw and for maintaining said lever in said position during a threading operation, substantially as described.

4. In a collapsible tube working machine, a tube supporting and rotating means, a slidably supported lever movable longitudinally of the tube sup orting and rotatlng means, a cutter on the ever, a continuously rotated means for sliding the lever, means for periodically rocking the lever to bring the cutter into operative position, and means on the lever for cooperation with the continuously rotated means only when the lever is moved to bring the cutter into operative position.

5. In a collapsible tube working machine, a bed, tube supporting and rotating means eeann over the bed, a longitudinall extending shaft under the bed, a second s aft parallel with the first located at the side of the bed of machine, means for rotating both shafts, a cutter supporting member with a cutter thereon, a cam .on the first shaft having means cooperating therewith for moving the cutter supporting means vertically into and out of operative position, and means on the second shaft cooperating with means on the cutter supporting member for transmitting longitudinally reeiprocable movement thereto.

In testimony whereof I have hereunto set my hand.

WALTER T. DAVIS. 

